If the ridge vent (exhaust vent) is snow covered and The Edge Vent (intake vent) is snow covered what happens to the attic ventilation?
If they are both covered, then there will be no attic ventilation. Eventually, the snow will clear from both the peak and the eave and the attic ventilation system will be functioning once again. Keep in mind, the only reason The Edge Vent would be temporarily blocked is because of snow accumulation in the gutter installed below the product.
In the event that The Edge Vent is covered with snow when the ridge vent is clear, the ridge vent will evacuate heat and moisture via thermal buoyancy. Once The Edge Vent is no longer blocked, the balanced attic ventilation system will be working as normal.